#divMouse {
  width: 20rem;
  height: 20rem;
  border: 1px solid #ff0000;
}

/* 视频的部分 */
.video-box {
  width: 16rem;
  height: 9rem;
  position: relative;
  overflow: hidden;
}

.video-box video {
  height: 100%;
  width: 100%;
}

.mask-box {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0px;
  left: 0px;
  background-color: rgba(0, 0, 0, 0.5);
  color: #fff;
  display: flex;
  justify-content: center;
  align-items: center;
  transform: translateY(100%);
  transition: transform 0.5s;
}

.video-box:hover .mask-box {
  cursor: pointer;
  transform: translateY(0%);
}
